Resolution:
Description:
===========
How to retrieve the child concepts using TIBCO BusinessEvents Query Language (BQL) with parents extID

Environment:
===========
TIBCO BusinessEvents 4.x,5.x
All Operating Systems

Symptoms:
=========
BQL:
Select p from /Concepts/slave s where p@parent@extId = 'extIDParent'

fails with exception (Collocated query):
Error [SnapshotQueryManager-1] - [query.stream] [be.agent.query.internal.dynamic]
java.lang.RuntimeException: com.tibco.as.space.ASException: remote_exception
Caused by: com.tibco.as.space.ASRemoteException: java.lang.RuntimeException: deReference: 7, class com.tibco.cep.runtime.model.element.impl.Reference Rule Session is NULL
    at com.tibco.as.space.impl.InvocationDispatcher.invokeMember(InvocationDispatcher.java:218)
Caused by: java.lang.RuntimeException: deReference: 7, class com.tibco.cep.runtime.model.element.impl.Reference Rule Session is NULL
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.deReference(ConceptImpl.java:305)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.deReference(ConceptImpl.java:276)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.deReference(ConceptImpl.java:272)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.resolveConceptPointer(ConceptImpl.java:348)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.getParent(ConceptImpl.java:949)
    at com.tibco.cep.query.stream.impl.expression.attribute.ParentAttributeEvaluator.evaluate(ParentAttributeEvaluator.java:30)
    at com.tibco.cep.query.stream.impl.expression.attribute.ExtIdAttributeEvaluator.evaluate(ExtIdAttributeEvaluator.java:29)
    at com.tibco.cep.query.stream.impl.expression.comparison.EqualityEvaluator.evaluateBoolean(EqualityEvaluator.java:57)
    at com.tibco.cep.query.stream.impl.expression.bool.AndEvaluator.evaluateBoolean(AndEvaluator.java:55)
    at com.tibco.cep.query.stream.impl.expression.bool.AndEvaluator.evaluateBoolean(AndEvaluator.java:55)
    at com.tibco.cep.query.stream.impl.expression.bool.AndEvaluator.evaluate(AndEvaluator.java:41)
    at com.tibco.cep.query.stream.impl.expression.EvaluatorToExtractorAdapter.extract(EvaluatorToExtractorAdapter.java:53)
    at com.tibco.cep.query.stream.impl.rete.expression.ReteEntityFilterImpl.allow(ReteEntityFilterImpl.java:28)
    at com.tibco.cep.query.stream.impl.rete.integ.filter.InterpretingFilter.evaluate(InterpretingFilter.java:67)
    at com.tibco.cep.runtime.service.rmi.ASNonIndexedFilter.evaluate(SourceFile:23)
    at com.tibco.cep.runtime.service.rmi.RemoteInvocableMember.invoke(SourceFile:92)
    at com.tibco.as.space.impl.InvocationDispatcher.invokeMember(InvocationDispatcher.java:207)

    at com.tibco.cep.as.kit.map.SpaceMap.traceAsException(SourceFile:96)
    at com.tibco.cep.as.kit.rmi.InvocationHelper.buildAndInvoke(SourceFile:154)
    at com.tibco.cep.runtime.service.rmi.RemoteFilterRunner.invoke(SourceFile:111)
    at com.tibco.cep.runtime.service.rmi.RemoteFilterRunner.entrySet(SourceFile:46)
    at com.tibco.cep.runtime.service.dao.impl.tibas.ASEntityDao.entrySet(SourceFile:422)
    at com.tibco.cep.query.stream.impl.rete.integ.EntityLoaderImpl.init(EntityLoaderImpl.java:79)
    at com.tibco.cep.query.stream.impl.rete.integ.EntityLoaderImpl.resumeOrStartBatchLoad(EntityLoaderImpl.java:86)
    at com.tibco.cep.query.stream.impl.rete.service.SnapshotQueryFeeder$FeederJob.run(SnapshotQueryFeeder.java:227)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at com.tibco.cep.query.stream.monitor.CustomDaemonThreadFactory$FactoryDaemonThread.run(CustomDaemonThreadFactory.java:65)
Caused by: com.tibco.as.space.ASException: remote_exception
Caused by: com.tibco.as.space.ASRemoteException: java.lang.RuntimeException: deReference: 7, class com.tibco.cep.runtime.model.element.impl.Reference Rule Session is NULL
    at com.tibco.as.space.impl.InvocationDispatcher.invokeMember(InvocationDispatcher.java:218)
Caused by: java.lang.RuntimeException: deReference: 7, class com.tibco.cep.runtime.model.element.impl.Reference Rule Session is NULL
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.deReference(ConceptImpl.java:305)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.deReference(ConceptImpl.java:276)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.deReference(ConceptImpl.java:272)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.resolveConceptPointer(ConceptImpl.java:348)
    at com.tibco.cep.runtime.model.element.impl.ConceptImpl.getParent(ConceptImpl.java:949)
    at com.tibco.cep.query.stream.impl.expression.attribute.ParentAttributeEvaluator.evaluate(ParentAttributeEvaluator.java:30)
    at com.tibco.cep.query.stream.impl.expression.attribute.ExtIdAttributeEvaluator.evaluate(ExtIdAttributeEvaluator.java:29)
    at com.tibco.cep.query.stream.impl.expression.comparison.EqualityEvaluator.evaluateBoolean(EqualityEvaluator.java:57)
    at com.tibco.cep.query.stream.impl.expression.bool.AndEvaluator.evaluateBoolean(AndEvaluator.java:55)
    at com.tibco.cep.query.stream.impl.expression.bool.AndEvaluator.evaluateBoolean(AndEvaluator.java:55)
    at com.tibco.cep.query.stream.impl.expression.bool.AndEvaluator.evaluate(AndEvaluator.java:41)
    at com.tibco.cep.query.stream.impl.expression.EvaluatorToExtractorAdapter.extract(EvaluatorToExtractorAdapter.java:53)
    at com.tibco.cep.query.stream.impl.rete.expression.ReteEntityFilterImpl.allow(ReteEntityFilterImpl.java:28)
    at com.tibco.cep.query.stream.impl.rete.integ.filter.InterpretingFilter.evaluate(InterpretingFilter.java:67)
    at com.tibco.cep.runtime.service.rmi.ASNonIndexedFilter.evaluate(SourceFile:23)
    at com.tibco.cep.runtime.service.rmi.RemoteInvocableMember.invoke(SourceFile:92)
    at com.tibco.as.space.impl.InvocationDispatcher.invokeMember(InvocationDispatcher.java:207)

    at JRemoteService.invoke(JRemoteService.cpp:314)
    at com.tibco.as.space.impl.ResultHelper.MakeInvokeResultList(ResultHelper.java:83)
    at com.tibco.as.space.impl.ASSpace.invokeMembers(ASSpace.java:671)
    at com.tibco.as.space.impl.ASSpace.invokeSeeders(ASSpace.java:708)
    at com.tibco.as.space.impl.ASSpace.invokeSeeders(ASSpace.java:1721)
    at com.tibco.cep.as.kit.rmi.InvocationHelper.buildAndInvoke(SourceFile:140)
    ... 12 more

Cause:
======
BQL syntax

Resolution:
========
Update BQL and use:

select s from /Concepts/Slave s, /Concepts/Master m
              where m@extId = '&ltextIDMaster>' and s@parent = m;